Mutations Flashcards
U2L5
What are Mutations?
Mutations are changes in the DNA sequence that are inherited.
What are the two types of mutations?
Point Mutations and Chromosomal Mutations
What are Point Mutations?
Point mutations is essentially a change which is caused by a change in a single base pair, (A changes to a T or a G gets inserted into the sequence).
What are Chromosomal mutations?
It’s when entire regions of a chromosome are altered (an entire gene section gets deleted).
What is the general idea of a frameshift mutation?
A frameshift mutation is essentially when the reading frame of an mRNA strand gets changed due to Insertion and/or Deletion. This causes the reading frame to be shifted and causes the Polypeptide Chain to be different.
What is Insertion and Deletion?
Insertion: Base Pair gets added to the DNA sequence.
Deletion: A base pair gets removed from the DNA sequence.
If the insertion or deletion occurs in a multiple of three, the reading frame will NOT be shifted
What is substitution?
It’s when one base pair is exchanged for another.
This is a type of Point Mutation.
What is Silent Mutation?
Silent mutation is when the amino acid is identical to the original sequence.
What is a missense mutation?
A Missense mutation is when the resulting amino acid is different from the original sequence.
What is a nonsense mutation?
A nonsense mutation is when the substitution causes the STOP codon to be read earlier, terminating the production of the polypeptide chain and making it premature.
